The Intergovernmental Panel on Climate Change (IPCC) has released the most comprehensive study ever on global warming, prepared by more than 200 scientists over two years. It concludes that, if the world continues to emit greenhouse gases at current rates, we will face warming of more than 2 degrees Celsius, compared with pre-industrial levels, within two to three decades. This is hugely significant because all countries have agreed that temperature rises should be restricted to no more than 2 degrees, thus increasing prospects of preventing "runaway" climate change.

The study also concludes that it is "extremely likely" that human activity has caused most of the increase in global temperature in recent decades.

The report will be welcomed by many, at a time when it may seem hard not to be pessimistic about the global battle to manage the huge risks of climate change. Moreover, in some places, climate change sceptics appear to be winning the battle for public opinion.

However, there are signs we may be reaching a turning point. If one examines what is already happening at national and sub-national level across the world, a relatively encouraging picture emerges.

Domestic laws and regulations are being passed at an increasing rate - in stark contrast to the pace of progress in UN-driven international negotiations. In 2012 alone, according to a report published by Globe International, 32 of 33 surveyed countries (which account for over 85 per cent of global greenhouse gas emissions), including the US and China, have introduced or are moving towards significant climate or climate-related legislation and regulation.

This is nothing less than game-changing.

Developing countries, which will provide the motor of global growth in the coming decades, are mainly leading this drive. Many are concluding that it is in their national interest to reduce greenhouse gas emissions by embracing low-carbon growth, and to better prepare for the impact of climate change.

They see that expanding domestic sources of renewable energy not only cuts emissions but also increases energy security by reducing reliance on imported fossil fuels. Reducing energy demand through greater efficiency cuts costs and increases competitiveness. Improving resilience to the impact of climate change also makes sound economic sense. Many governments and companies realise a green race has started and they are determined to compete.

It follows, therefore, that advancing domestic legislation on climate change, and experiencing the benefits of reducing emissions, is a crucial building block to create the political conditions for a comprehensive, global climate agreement. Domestic laws give clear signals about policy direction, increasing confidence and reducing uncertainty, particularly for the private sector.

With negotiations on a post-2020 comprehensive global deal due to conclude in 2015, it is unlikely that an agreement will be reached unless more domestic frameworks are in place in key countries. Rather than lowering long-term ambitions, now is the time for countries to invest more in tackling climate change, to help create the conditions for a global treaty.

Andrew Hammond was formerly a special adviser in the UK government, and a senior consultant at Oxford Analytica

This article appeared in the South China Morning Post print edition as The heat is on